Subway hieroglyphs decoded

Thermometer sticker. Look up and you’ll see these tiny stickers plastered to the ceiling of every subway car. No, they’re not there to mock Jeremy Piven. The HVAC (heating, ventilation and air-conditioning) target-temperature decals were installed in 2008 so that workers could use laser thermometers (how space age!) pointed at the decals to record temperatures and make sure you’re not sweating. Last summer they checked them whenever the outside temp spiked above 85 degrees, and then tuned car climates to 78 degrees or below. If only the West 4th Street sauna could get the same treatment.

Car number. Each of the cars in the subway system has a unique number, falling anywhere between 1101 and 9592. They’re numbered consecutively within sets (as when the MTA orders a group of four or five cars together). The fleet is at 6,418 subway cars right now, and cars can switch among lines (numbered to numbered or lettered to lettered—surely you’ve noticed how the 3 train is tinier than the F).

Star on the wall. No, you’re not special if you sit on a seat under one of the MTA’s star stickers. They’re there to “provide information” (the MTA’s mum on what kind) to maintenance crews who deal with the car’s innards.

Door and emergency brake numbers. Seems like everything has a number at the MTA, even the individual subway doors. Again, they’re for identification and help maintenance crews when defects arise—you try describing which door is broken when you have 6,418 subway cars to deal with: “It’s the door across from the bunion ad. No, the other bunion ad. No, the other one!”